An important analysis to be made by doctors of chiropractic relates to determining whether or not one of the patient's legs is shorter or longer than the other. A difference in leg lengths could mean that the skeleton is generally out of alignment or that a spinal problem exists.
Typically, the doctor of chiropractic, or any physical therapists and any orthopedic practioner, finds it critical to determine if a leg length difference exists, since, with either skeletal misalignment or spinal abnormality, the condition will get worse if untreated.
In present practice, various techniques and tools have been used for determining leg length differences. For instance, U.S. Pat. No. 3,520,293, invented by Atherholt, shows a device for measuring leg length differences by a rather complex device relying upon force measurements. U.S. Pat. No. 3,196,551 by Provost, et al, is similar in terms of its complexity for the same purpose.
In terms of eliminating complexity, most practitioners have avoided the complex devices and tools by using a hand-measurement test which has proven to be quite inaccurate. In the hand-measurement test, the patient lies on his belly and equal hand pressure is applied to pull the legs to their full length, and a difference is noted or measured by an assistant. In such cases, a check of the noted difference is performed by having the patient bend his or her knees and the comparison is again made by either noting the difference or the measurement.